1 files changed, 56 insertions, 0 deletions
diff --git a/test/CodeGen/SystemZ/cmpxchg-02.ll b/test/CodeGen/SystemZ/cmpxchg-02.ll
new file mode 100644
index 0000000000000..cc3452320b3d0
--- /dev/null
+++ b/test/CodeGen/SystemZ/cmpxchg-02.ll
@@ -0,0 +1,56 @@
+; Test 16-bit compare and swap.
+;
+; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s -check-prefix=CHECK-MAIN
+; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s -check-prefix=CHECK-SHIFT
+
+; Check compare and swap with a variable.
+; - CHECK is for the main loop.
+; - CHECK-SHIFT makes sure that the negated shift count used by the second
+;   RLL is set up correctly.  The negation is independent of the NILL and L
+;   tested in CHECK.  CHECK-SHIFT also checks that %r3 is not modified before
+;   being used in the RISBG (in contrast to things like atomic addition,
+;   which shift %r3 left so that %b is at the high end of the word).
+define i16 @f1(i16 %dummy, i16 *%src, i16 %cmp, i16 %swap) {
+; CHECK-MAIN: f1:
+; CHECK-MAIN: sllg [[SHIFT:%r[1-9]+]], %r3, 3
+; CHECK-MAIN: nill %r3, 65532
+; CHECK-MAIN: l [[OLD:%r[0-9]+]], 0(%r3)
+; CHECK-MAIN: [[LOOP:\.[^ ]*]]:
+; CHECK-MAIN: rll %r2, [[OLD]], 16([[SHIFT]])
+; CHECK-MAIN: risbg %r4, %r2, 32, 47, 0
+; CHECK-MAIN: cr %r2, %r4
+; CHECK-MAIN: j{{g?}}lh [[EXIT:\.[^ ]*]]
+; CHECK-MAIN: risbg %r5, %r2, 32, 47, 0
+; CHECK-MAIN: rll [[NEW:%r[0-9]+]], %r5, -16({{%r[1-9]+}})
+; CHECK-MAIN: cs [[OLD]], [[NEW]], 0(%r3)
+; CHECK-MAIN: j{{g?}}lh [[LOOP]]
+; CHECK-MAIN: [[EXIT]]:
+; CHECK-MAIN-NOT: %r2
+; CHECK-MAIN: br %r14
+;
+; CHECK-SHIFT: f1:
+; CHECK-SHIFT: sllg [[SHIFT:%r[1-9]+]], %r3, 3
+; CHECK-SHIFT: lcr [[NEGSHIFT:%r[1-9]+]], [[SHIFT]]
+; CHECK-SHIFT: rll
+; CHECK-SHIFT: rll {{%r[0-9]+}}, %r5, -16([[NEGSHIFT]])
+  %res = cmpxchg i16 *%src, i16 %cmp, i16 %swap seq_cst
+  ret i16 %res
+}
+
+; Check compare and swap with constants.  We should force the constants into
+; registers and use the sequence above.
+define i16 @f2(i16 *%src) {
+; CHECK: f2:
+; CHECK: lhi [[CMP:%r[0-9]+]], 42
+; CHECK: risbg [[CMP]], {{%r[0-9]+}}, 32, 47, 0
+; CHECK: risbg
+; CHECK: br %r14
+;
+; CHECK-SHIFT: f2:
+; CHECK-SHIFT: lhi [[SWAP:%r[0-9]+]], 88
+; CHECK-SHIFT: risbg
+; CHECK-SHIFT: risbg [[SWAP]], {{%r[0-9]+}}, 32, 47, 0
+; CHECK-SHIFT: br %r14
+  %res = cmpxchg i16 *%src, i16 42, i16 88 seq_cst
+  ret i16 %res
+}